I'm a big fan of open source STM publishing, but there are still costs involved. You cannot publish a serious, peer-reviewed open journal without paying staff and expenses.
I point this out because there is a serious myth held by Internet users that goes like this: if I can access it for free, then it must cost nothing to produce. A corollary is: If you don't have to pay money to print and distribute magazines, then an online magazine should cost nothing to produce.
We were talking about these issues in the late 90s at AAAS. We were very worried come 2000-2001 that making Science Online available for "free" to universities and labs would come at some expense to the parent organization. We made Science Online available for an affordable price and as I understand it, that did have repercussions a few years later.
This all relates to the common problem that all online media have in paying the bills. Internet users rarely will buy a subscription to an online magazine or journal. So most online publishers try to make money through Internet advertising. This phenomenon really hurts alternative media, who really can't run much advertising. I think that the recent demise of several alternative political magazines can be attributed in part to Internet factors.